Roots: The radio broadcast refers to the premiere of the 2006 movie version of Miami Vice (c.f. The Reaping) Tegan paraphrases Kylie Minogue ("I never could get you out of my head") For the likely origin of the phrase '8687' see the box-out below. Mention is made of Nick Cave and Billie Piper (perhaps for the only time ever in the same sentence). James Blunt's You're Beautiful. Alan refers to Agatha Christie's Hercule Poirot, Miss Marple, and Enid Blyton's Famous Five. Fictional band The Bricklayers and their new single Westway may be a nod to 80s Australian band Men at Work and their single Down Under.

Intertextuality: The implication that James Clarke is working for the Forge is confirmed in the short story Twilight's End in Short Trips: Defining Patterns.

The recurrence of the phrase "there is nothing to fear" is a theme of the Big Finish series Cyberman.

The Doctor's uneasiness at the suggestion he may have to explain in which years he was working for UNIT mimics ongoing fan debate

Dialogue Triumphs: Alan to the Doctor: "If you were in your seventh incarnation you'd know. He knows everything."

"Australians don't do nostalgia" "-Of course you do. Everyone on Earth does nostalgia - it's your version of time travel."

The Doctor and Tegan: "No worries - is that right? That's what you Australians say, isn't it?" "-Not while you're around."

Everyone else and the Doctor: "We should have a gun or something" "-Oh good idea; that way people die."

"I work for... humanity" "-So do I - pay's not too good, is it?"

Double Entendres: "The Brisbane Banger's my specialty"

Continuity: Following the deaths of Janine Foster and Mrs van Gysegham in Baltimore 1984, Katherine Chambers fled Fell's Point at the suggestion of her university friend James Clarke. Heading to his birthplace of Brisbane they took with them Katherine's crippled and near-comatose brother Nate on an "alien hover-bed" provided by James and his likely contacts who are specialists in sourcing and adapting xenotech - an implicit reference to the Forge. With her Katherine took the remaining half of the Cyber-conversion device, a mixture of Cyberman and Gallifreyan technology which James uses in his own experiments and Katherine employs in her treatment of Nate, turning into a semi-formed Cyberman. Katherine set up a medical clinic in Brisbane eleven years ago, along with British tourist Eve (originally from South London), who has an IQ of 145 and ostensibly met Katherine while travelling (although Eve has connections with James as well.) The alien technology spirited away by James at the end of this story crops up again in St Gart's, including System - still voiced by Eve, which James appears to have developed himself, with support by Katherine.

The Gogglebox as featured here is only a couple of days old and features among its staff one Alan Fitzgerald, a history student who refuses to travel with his idol the Doctor because he knows of no historical record involving him joining in the Time Lord's adventures. Alan explains that the Doctor is a recurring figure throughout Earth and humanity's greatest events, from their creation of fire, to its ultimate end (see: Links).

Tegan's birthday is September 22 (she is 46), a date she shares with Doctor Who actress and singer Billie Piper. Some twenty years ago, during her travels with the Doctor, she developed a brain tumour which has slowly grown and is presumed inoperable, giving Tegan only months to live. After leaving the Doctor she returned to Brisbane and took over her father's stock feed company, Verney Food Supplies

The Doctor is travelling alone, having left his current companions in Monte Carlo (see: Links). Despite (or anticipating) the Doctor's attempts to manufacture a memory trigger for himself to prevent crossing his own future time stream, something will cause the Doctor to lose some of the memories of his Fifth incarnation. What will cause this has not yet been revealed (see Box-out). In this instance the Doctor and Eve/System choose it from the name of the pub where Tegan has her 46th birthday gathering. Tegan feeds the Doctor his celery lapel (he says he hates celery, and doesn't actually eat it), while the Doctor (unsuccessfully) attempts to use Venusian Aikido to smash a van window (given that this is a defensive martial art it's no surprise he fails, or perhaps this incarnation has little aptitude in it?) System uses the Doctor's innate telepathic ability, boosting it, to forget the present events and not endanger his future self with achromous knowledge, secured by the trigger '8687' signal. The Doctor tells System he can shut down his entire body and mind, ending his life (presumably without regeneration), by force of will.

Links: This story is an out-of-sequence follow-up to The Reaping, which also features the Gogglebox. The Tenth Planet. Terror Firma (The Doctor means to visit the ice caves of Shabadabadon). Venusian Aikido (Inferno et al) The Veiled Leopard (mention is made of the Doctor dropping off his companions in Monte Carlo). 100,000 BC (humanity's discovery of fire), The Visitation (Alan asks about the Doctor's involvement with the "first" Great Fire of London), The Chase (ditto the Marie Celeste) and UNIT. Tegan makes reference to Daleks (Resurrection of the Daleks), the Mara (Kinda, Snakedance) and Cybermen (Earthshock - Tegan tells Katherine that she knows the Doctor "won't change history to save someone", as proved in the same story and Adric's death). The name of her company is taken in part from her grandfather Andrew Verney (The Visitation). Singularity (World War Five), The Harvest (St Gart's and System). Alan says there are rumours the Doctor will be present at 'the very end' - presumably of the human race, but perhaps Earth, which may or may not be a nod to The End of the World. The final voice-over is given to future companion Hex.

Future History: The opening radio broadcast (as in The Reaping) refers to World War Five and a loss of contact with "outer colonies"

Somewhat muted by the return proper of Tegan in 2010, in 2006 of course this was a Big Deal, and clearly intended to be Tegan's swansong; a brave decision on her part to put the Doctor at arm's length and face her destiny on her own terms. TV continuity has had its say as well, but Tegan's decision is the smartest thing in this otherwise muddled story, a definite poor relation to co-release The Reaping. In its day, though, a daring final lap for both Tegan and Janet Fielding.

8687 AND THE DOCTOR'S MEMORY

Three of Joseph Lidster's stories for 2006 contain similar elements which imply a story arc being built upon, one yet to be resolved since Big Finish Producer Gary Russell's departure in the same year. This story's phrase '86,87' may be an obvious reference to the Big Finish release number for this story (number 86) and that of The Reaping, its immediate successor. Alternatively it could be a nod to the Cybermen's first story, taking place at the end of 1986 and the beginning of 1987. Regardless, it presents a loose end that Big Finish have yet to tie up, namely the Fifth Doctor's loss of memory that contributes to his involvement with individuals and circumstances he is to later return to in his Sixth incarnation, the numeric phrase being a mnemonic trigger. The phrase is one of several recurring elements in Big Finish's 2006 series, including the White Rabbit pub (The Harvest, The Kingmaker, and later featuring in 2011's Project: Destiny), and the involvement of The Forge, which can at least for the moment in 2012 be assumed to have been resolved. In addition to these some fans also include the question of the Doctor's memory of Erimem, a companion of the Fifth Doctor notably (albeit understandably) not namechecked during his regenerative flashbacks in The Caves of Androzani.

The curious element in the '8687' conceit is that the Sixth Doctor doesn't remember his past events when he encounters the people and events that will bring them into being - on several; occasions during The Reaping the phrase is said to both him and Peri, and it goes over his head. The inference here could be that there were one or more stories intended to take place between The Gathering and The Reaping in which something or someone would interfere with the Doctor's memory and remove the mnemonic trigger. If this erasing of the Doctor's memory took place during the last stages of his Fifth incarnation (i.e. between The Bride of Peladon and The Caves of Androzani), then it may also point to a tampering of his memory of Erimem. The obvious candidate here is Mission of the Viyrans, which is centred on a deliberate rewriting of Peri's memories after she and the Doctor visit Grallista Social as respite immediately following their friend Erimem's departure. As the story is only told from Peri's perspective, it can't be known whether the Doctor was similarly subjected to a memory wipe by the Viyrans (indeed, neither mention Erimem in stories past Mission.)

We must exercise caution here, however, as it is plainly obvious that the Viyran stories are a post-Russell arc, and the question of the Doctor's memory of his past companions is only an element of the last story of the arc which, intriguingly, features the Doctor visiting Grallista Social to ease his mind after the sudden departure of a companion who is partially created from memories doctored by the Viyrans. To lose one's memories of one former companion on Grallista Social by Viyran intervention may be regarded a misfortune, to lose two looks like carelessness; but as fan theories go, it may be all listeners can go by, at least until the return of Gary Russell to Big Finish brings about an explanation.